Debonder compositions and surfactants are widely used in the paper industry. For example, such compositions are used in connection with recycle fiber. There is disclosed in U.S. Pat. No. 5,582,681 to Back et al. a method of making a sanitary paper product from newspaper involving pulping the newspaper in water with agitation to produce a pulp slurry at a consistency between 3 and 12% and a pH below about 8.0; adding to the slurry an enzyme selected from the group consisting of cellulase, hemicellulase, and lipase and maintaining the pulp slurry at a temperature above about 100° F. for at least 15 minutes; and using the enzyme treated pulp as a major source of fiber in the paper making to produce the sanitary napkin product. As reported in the '681 patent, there is a synergistic relationship between the combination of surfactant and an enzyme. Nonionic surfactants are preferred for addition with the enzyme; however, in some cases a cationic surfactant can be used, such as an imidazole compound or quaternary ammonium compounds. See column 10, lines 7–40.
There is disclosed in U.S. Pat. No. 5,622,597 to Callen et al. a process for deinking recycled paper using a pressurized deinking module to separate ink from paper pulp stock. The addition of salts of imidazolinium based compounds with alkyl, alkenyl and amidoethyl side chains to the pulp slurry at the beginning of the pressurized deinking module cycle removes ink more effectively. Surfactants are used in the deinking process, for example, an ethylene oxide/propylene oxide nonionic surfactant (compare Example A), as well as imidazolinium methylsulfate (Example 1), see column 4.
Debonder compositions are often added at the wet end of a process for making tissue paper as disclosed in U.S. Pat. No. 4,441,962 to Osborn, III and U.S. Pat. No. 4,351,699 also to Osborn, III. There is disclosed in these patents a method of making tissue paper webs including the steps of forming an aqueous paper making furnish from paper pulp, and adding at least one specified quaternary ammonium compound and at least one specified nonionic surfactant. The quaternary ammonium compounds are trimethylalkylenyl, methylpolyoxy-ethylene alkyl and methylpolyoxyethylene alkylenyl quaternary ammonium compounds. The nonionic surfactants are ethylene oxide adducts of fatty alcohols and fatty acids.
There is disclosed in U.S. Pat. No. 5,698,076 to Phan et al. a method of making absorbent paper products such as paper towels, facial tissues and toilet tissue by way of the incorporation of a vegetable oil based quaternary ammonium chemical softening compound. Examples of preferred vegetable oil based quaternary ammonium chemical softening compounds according to the '076 patent, include diester di(oleyl)dimethyl ammonium chloride (DEDODMAC) derived from canola oil and/or high oleic safflower oil. It is noted in the '076 patent that complex quaternary ammonium compounds are sometimes used with nonionic surfactants such as ethylene oxide and propylene oxide reacted with an alcohol in order to overcome any decrease in absorbency caused by the use of cationic debonding compounds. See Column 2, lines 6 through line 18. It is noted in the '076 patent that the claimed process may be used in connection with recycled fiber (column 4, lines 54–55) and that optional ingredients such as polyhydroxy compounds and nonionic surfactants (alkoxylated materials) may be added so long as softening is not adversely affected (See column 11, line 23 and following, as well as column 13 line 6 and following. The nonionic surfactants of the '076 patent are characterized by a hydrophilic-lipophilic balance (“HLB”) of from about 7 to about 20. See column 11, lines 53–63.
U.S. Pat. No. 5,730,839 to Wendt et al. discloses a method of making tissue products through creping under closed pocket conditions. In connection with this process, debonders/softening agents are used which include several imidazolinium quaternary compounds. The imidazolinium quaternary compounds can be added to the tissue making process at any point prior to the creping blade but are preferably added at the wet end and most preferably added to the thick stock prior to the web formation where the consistency of the aqueous paper making fiber suspension is about 2% or greater. In addition to the imidazolinium quaternary compounds, nonionic surfactants may also be added to the tissue at the wet end of tissue making process to further enhance the softness of the final product.
Examples of useful classes of nonionic surfactants include alkylphenol ethoxylates, aliphatic alcohol ethoxylates, fatty acid alkoxylates, fatty alcohol alkoxylates, block copolymers of ethylene oxide and propylene oxide, condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylenediamine and condensation products of propylene oxide with the product of the reaction of ethylene oxide and ethylenediamine. See column 3, lines 11 through 46.
U.S. Pat. No. 5,753,079 to Jenny et al. reports enhanced paper debonding and softening by producing paper from an aqueous suspension of fibers which contains one or more cationic agents and one or more ethylene oxide/propylene polymer surfactants.
U.S. Pat. No. 4,447,294 to Osborn, III discloses a process for making soft absorbent tissue paper webs and the webs produced by the process. In the first step the furnish of papermaking fibers and a wet strength resin is provided. A web fibrous web is made from the furnish and the wet web is dried after which the wet strength resin in the web is at least partially cured and the nitrogenous cationic debonding agent is then incorporated into the dried web.
U.S. Pat. No. 5,279,767 to Phan et al. discloses a chemical softening composition useful in fibrous cellulosic materials. There is provided in accordance with the '767 patent, chemical softening compositions including a mixture of quaternary ammonium compound and polyhydroxy compounds. Preferred quaternary ammonium compounds include dialkyldimethylammonium salts such as di(hydrogenated) tallow dimethylammonium chloride and di(hydrogenated) tallow dimethylammonium methylsulfate. Preferred polyhydroxy compounds are selected from the group consisting of glycerol and polyethylene glycols and polypropylene glycols having a weight average of a molecular weight from about 200 to 4000. The chemical softening compositions are prepared by first mixing the polyhydroxy compound into the quaternary ammonium compound at a specific temperature range wherein the polyhydroxy compound is miscible with the quaternary ammonium compound and then diluting the mixture at an elevated temperature to form an aqueous vesicle dispersion suitable for treating fibrous cellulosic material. The chemical softening compositions disclosed in the '767 patent are primarily intended for softening disposable paper products such as tissues and towels. See, for example, U.S. Pat. No. 5,240,562 of Phan et al.